Patent GB-173786-A (GB)
Title: Process for the production of esters and materials containing esters from olefines
IPC: C07C67/04
Filed: 1920-06-30
Abstract: Solvents for pyroxylin, consisting of mixtures of light saturated hydrocarbons with esters of lower fatty acids, are obtained by heating together the fatty acids, a catalyst such as sulphuric or a similar acid, and a mixture of olefines with saturated hydrocarbons, as got for instance by cracking gasoline. petroleum products obtained by drastic cracking are not suitable unless di-olefines and other complex unsaturated hydrocarbons are first removed as a sludge by treatment with say 1/2 -1 per cent of strong sulphuric acid.  The sulphuric acid used in esterification may be of sp. gr. 1.8, and preferably does not become diluted below a strength corresponding to sp. gr. 1.7 during the reaction; it may amount to 10 per cent or less of the weight of glacial acetic acid used.  The organic acid is preferably in excess of the theoretical quantity.  A salt such as calcium acetate and an additional quantity of sulphuric acid may replace the organic acid.  Esterification may be effected in a digester with a reflux condenser, at atmospheric or higher pressures, and is sufficiently complete in a few hours.  From the product the acids may be removed by washing with water and with sodium carbonate solution, and any calcium sulphate &c. by centrifuging, filtering, &c.ALSO:Esters of lower fatty acids are obtained by heating together olefines, the fatty acids, and a catalyst such as sulphuric or a similar acid.  The olefines may be pure or mixed with saturated hydrocarbons, for instance in the form of cracked gasolene or petroleum still gases.  Petroleum products obtained by drastic cracking are not suitable unless di-olefines and other complex unsaturated hydrocarbons are first removed as a sludge by treatment with say 1/2 -1 per cent of strong sulphuric acid. The sulphuric acid used in esterification may be of sp. gr. 1.8, and preferably does not become diluted below a strength corresponding to sp. gr. 1.7 during the reaction; it may amount to 10 per cent or less of the weight of glacial acetic acid used. The organic acid is preferably in excess of the theoretical quantity.  A salt such as calcium acetate and an additional quantity of sulphuric acid may replace the organic acid. Esterification may be effected in a digester with a reflux condenser, at atmospheric or higher pressures, and is sufficiently complete in a few hours.  From the product the acids may be removed by washing with water and with sodium carbonate solution, and any calcium sulphate &c., by centrifuging, filtering, &c.  The esters from hydrocarbon oils of b.p. 100 DEG  C. generally boil above 115 DEG  C. and are thus readily separable from the saturated hydrocarbons by distillation.  Alternatively, the esters may be dissolved from the crude product by sulphuric acid of sp. gr. 1.57, and recovered by dilution; further purification may be effected by distillation.ALSO:Cracked gasolene or the like containing olefines and saturated hydrocarbons, is heated with lower fatty acids and a catalyst such as sulphuric or a similar acid, so that the olefines are converted into esters, which can then be separated from the saturated hydrocarbons.  Petroleum products obtained by drastic cracking are not suitable for the treatment, unless di-olefines and other complex unsaturated hydrocarbons are first removed as a sludge by treatment with say 1/2 -1 per cent of strong sulphuric acid.  The sulphuric acid used in esterification may be of sp. gr. 1.8, and preferably does not become diluted below a strength corresponding to sp. gr. 1.7 during the reaction; it may amount to 10 per cent or less of the weight of glacial acetic acid used.  The organic acid is preferably in excess of the theoretical quantity.  A salt such as calcium acetate and an additional quantity of sulphuric acid may replace the organic acid. Esterification may be effected in a digester with a reflux condenser, at atmospheric or higher pressures, and is sufficiently complete in a few hours.  From the product the acids may be removed by washing with water and with sodium carbonate solution, and any calcium sulphate &c. by centrifuging, filtering, &c.  The esters from hydrocarbon oils of b.p. 100 DEG  C. generally boil above 115 DEG  C., and are thus readily separable from the saturated hydrocarbons by distillation.  Alternatively, the esters may be dissolved from the crude product by sulphuric acid of specific gravity 1.57.